Continuous AA DPS Explained

[LittleWhiteMouse]

Please note the addition following "The Bug" section regarding insight provided by Sub_Octavian.
- Mouse, June 1st, 2019.

 

Before I get started, I want to thank StuntMan9630 and @Arashi_ishigawa for their assistance.

This project explains why I haven't published my Lenin review yet.  I've been sidetracked -- namely understanding how Continuous AA Damage worked, why it appears more effective for some ships than for others.  I mean, how am I supposed to properly evaluate the relative effectiveness of AA firepower if I don't understand the fundamentals?  Well, now I do and it's all crap because of a bug.  But more on that later.  Let's talk about how continuous AA DPS is supposed to work!

A Throne of Lies

Oh, port stats... how I loathe thee.

For this article, I'm not concerning myself at all with flak explosions.  I'm just talking about the pulses of direct damage a ship's AA mounts deal to attacking aircraft.   For veterans of World of Warships, the following should come as no surprise:  The in-port information about your anti-aircraft defense is horribly misleading.  While technically correct, the values like "continuous damage per second" do not reflect the effectiveness of a given aura's damage output.  Here's why:

1. Each aura deals a fixed amount of damage per shot.
2. Each aura has its own reload time.

These are both hidden values and they're important ones.  They tell you how much damage you can expect to cause to aircraft an aura and how often you can expect to see those numbers appear.  The variance in these two numbers is tremendous and the difference between them dictate whether or not a ship has good anti-aircraft firepower or not.  A slow firing gun might deliver massive alpha strikes to aircraft but only manage to fire once (if at all) before aircraft sail out of their range.  This, in part, explains why ships can rack up some pretty impressive aircraft damage totals without shooting anything down.  It also explains why you can see your AA gun animations chattering away and yet you receive no tally of damage -- the planes got out of range before someone could line up the shot to fire.

In short, the "Continuous Damage per Second" value in port is a crock and isn't worth heeding.  Some of the ships you might consider to be excellent AA powerhouses because of high AA DPS values may, in fact, be pretty crappy.

Bringing the Thunder

So if we can't trust the client to tell us what we need to know, we have to go digging.  Unfortunately, you're not going to find the information you need anywhere except for third party sites or from your friendly neighbourhood dataminer.  I used gamemodels3d.com to pull the following values (and I highly recommend the site for anyone that's looking to learn more about World of Warships). 

Numbers made pretty with colours!

So there's a lot of numbers and not a lot of meaning here, so I MS Painted some brief explanations.  These are the values for the (still Work in Progress) HMS Thunderer, the upcoming tier 10 premium Royal Navy battleship.  She uses the same 133mm/50 dual-purpose guns as HMS Conqueror and her performance with these weapons has been cloned in this first iteration.  So, let's go over what we see here.

• Hit Chance is an accuracy coefficient.  You'll see this value repeated in port but how it gets used will throw you for a loop.  It has nothing to do with how accurate your Continuous AA DPS is.  Instead, it slows down the rate of fire of a given weapon.
• Area Damage is how much damage is done per hit.  This is the number you should see show up in the UI any time your Continuous DPS scores a hit against an enemy aircraft.  This value can be modified by skills, consumables and player actions as we'll discuss later.  However, if you were to populate a Training Room with active Conqueror bots and fly your unbuffed aircraft within the 3.5km to 6.0km reach of her 133mm guns while dodging flak perfectly, this would be the amount of damage done to your aircraft with every pulse.
• Area of Damage Frequency is ostensibly your reload time... except it's not.  This value gets modified by your Hit Chance -- specifically, you divide your Area of Damage Frequency by Hit Chance to get the actual time, in seconds, of each pulse.  In the case of Thunderer here, this means her long range aura only shoots once every 4.95 seconds.  This number can be modified through player actions.
• Area Damage Per Sec is where we get that useless in port AA-DPS stat.  This is imply the Area Damage divided by Area of Damage Frequency and it doesn't account for the Hit Chance coefficient which is hella important.

These are pretty damn important values to know and speaks a lot about how anti-aircraft firepower works in World of Warships.  The only way to find these values is to dig.  These values could also be changed without the players knowing and we're reliant upon dataminers making the discovery or Wargaming letting us know.

Modifications

Player actions can modify how much Continuous Damage a given aura does and how frequently it fires.  This is STUPIDLY IMPORTANT to understand in order to grasp how to make the most out of your anti-aircraft firepower and for evaluating the potential AA strength of a given ship.  This will also save you spending credits, doubloons and captain experience, so let's go over these thoroughly.

There are four ways to increase the amount of Continuous Damage done per pulse.  In order from lowest to highest:

• November Echo Setteseven signal adds 5%.
• Basic Fire Training commander skill adds 10%.
• AA Guns Modification 2 adds 15%.
• Defensive AA Fire adds 50% to 200% for select mounts.

These bonuses are multiplicative.  Let's take Thunderer as our example.  She normally deals 450 damage every 4.95 seconds.  Fully upgraded and using her (still WIP) Defensive AA Fire consumable which is oh-so rare on a battleship, she can increase this to 1,195 damage ever 4.95 seconds.  With DFAA inactive, this will drop back down to 597 damage every 4.95 seconds.

The rate at which pulses occur can also be modified through the use of Sector Reinforcement.  Sector Reinforcement greatly increases the number of attacks made and varies per ship type while aircraft are targeted within their aura.

• Cruisers and Battleships gain 25%
• Destroyers gain 50%
• Aircraft Carriers gain 60%
• These values can be increased by 20% (multiplicative) with the Manual Fire Control for AA Guns commander skill.  With this skill, cruisers and battleships fire 50% faster.  Destroyers fire 80% faster.  Aircraft carriers fire 92% faster (!)
• NOTE: using Sector Reinforcement slows down the rate of fire in the opposite sector.  Proper management is key.

Restating our example above, just through the use of Sector Reinforcement, our stock Thunderer now fires every 3.71 seconds.  Fully upgraded, this turns into 2.48 seconds.  However, if you've mismanaged your Sector Reinforcement, our stock Thunderer now fires 450 damage every 6.19 seconds.  Fully upgraded, this gets even worse with it dropping down to 7.43 seconds.

Zero Counterplay

Of course, the carrier player isn't going to let you have everything your own way.  They can mitigate the amount of Continuous Damage they receive in the following ways:

• Aircraft Armour commander skill reduces the amount of Continuous Damage received by 10%.  This skill is very commonplace so you can expect it to influence your numbers often.
• Attack Runs reduce the amount of Continuous Damage received by 50%.  Whenever planes begin their attack, the amount of damage they receive is slashed in half.  Left click your way to victory.
• Slingshot Dropping uses (and abuses) an immunity window provided to dive bombers after they drop ordnance.  They are completely immune to Continuous Damage for 5 seconds + the bomb drop time.
• Destroying AA mounts reduces the amount of Continuous Damage proportionately.  So if you started with eight medium-caliber AA mounts and three get destroyed, your Continuous Damage drops by 3/8ths. 

Similarly, they can increase or decrease how often they're hit by Continuous Damage by loitering in or speeding through a given aura.  Inexperienced carrier players are more likely to manoeuvre and come about while still within a ship's anti-aircraft aura, stacking Continual Damage (and how nice of them to be so obliging!).  Contrarily, you can expect expert players to minimize their exposure time to Continuous Damage through use of line of sight blocking mechanics and speed.  Speed is of particular concern, given the following amount of distance covered per second in World of Warships:

• 100 knots = 0.27km/s
• 120 knots = 0.32km/s
• 140 knots = 0.38km/s
• 160 knots = 0.43km/s
• 180 knots = 0.48km/s
• 200 knots = 0.54km/s

Looking back at our 133mm guns on Thunderer, they have a 2.5km range (6km to 3.5km).  160 knot aircraft can cover that distance in 5.8 seconds.  Boosting up to 195 knots, they'll cross that same span a full second faster at 4.8 seconds.  Proper management of your fire sectors can mean the difference between shooting something down and doing no damage whatsoever.

The Bug

Atlanta is one of the ships hit hardest by the bug currently as she's reliant upon her long range, slower firing 127mm/38s to do most of the heavy lifting.

"But Mouse," you say, "your last example sounded hyperbolic.  Surely there's no way for aircraft to pass through an aura and take zero damage.  Shouldn't the AA guns open fire the moment an aircraft comes into range?"  Yes, yes they should.  They don't, but they should.

This is one of the problems with anti-aircraft firepower right now.  It needs to be rectified.  Currently, ships don't preload their anti-aircraft guns.  Yep, someone has to go run and fetch the ammo hoppers before your guns will shoot.  This means, using Thunderer as our example, that aircraft can sit in her long-range aura for 4.95 seconds before they take Continuous Damage.  Before the boost nerf, it was all too easy for aircraft carriers to rocket through some of the slower firing auras without taking a lick of damage.  It didn't matter how many damage boosts you applied, if you hadn't reinforced your sectors to increase your rate of fire, they were in and out before your guns would shoot once. Graf Zeppelin and Indomitable could make 0.7km/s with some of their strike aircraft, meaning that even if you did reinforce your sectors, there was long range AA that simply couldn't touch them.

Now, I have it from Wargaming that this will be fixed in the future -- and this might very well be THE AA-fix they've been alluding to.  This won't have much impact on rapid fire weapons, but it will be a sizeable buff to slower-firing guns which will go from no-shows to providing some pretty chunkular damage.  I dunno how long we have to wait, though.

---

Click the spoiler to read an update to this section.

Spoiler

Hi, everyone!

This is being written after this article was published and serves to correct a misunderstanding made when I asked Wargaming for clarification on these mechanics.  The delay between an aircraft entering an AA-aura and it opening fire isn't a "bug".  It's that way by design.  Whether that makes it better or worse in your eyes is up to you, gentle reader.  I'm not a fan, but I generally take the side that anti-aircraft firepower is on the weak side at the moment.  Sub_Octavian popped into this thread to offer his insights.  He makes a few points which I've turned into jpegs below.  You'll also find direct links to his posts found in this thread.

Thanks!  Hope this hasn't caused too many grumpy thoughts and/or confusion!

LittleWhiteMouse, June 1st, 2019

Link.

More different link.

 

---

Feeling Weird and Weird Feels

Nyooooooom!

Looking this over, it's evident to me that Wargaming built the backbone of anti-aircraft defense around the Sector Reinforcement mechanic.  In theory, it's hella powerful if used correctly with the right buffs.  Manual Fire Control for AA Guns is, hands down, the best AA skill for a ship to be using if they want to improve their aircraft killing power.  In practice, well, the bug undermines Continuous Damage rather significantly, more than halving the effective damage output of large-caliber AA guns in some respects.  The faster firing medium and short range AA guns are much less affected by such things.  Unfortunately, small and medium caliber AA mounts tend to pop to loud noises, never mind direct fire from HE shells, British cruiser SAP and aircraft delivered ordnance. 

It's no surprise to me that, on the whole, Sustained Damage feels underwhelming right now.  However, I think the problem is further compounded by simply not understanding how much damage is done and how often.  There isn't a lot of consistency either.  It seems the values for rate of fire and damage are based on not only which guns are used by how many.  Here's an example of four tier 8 American ships, all using 127mm/38s, 40mm Bofors and 20mm Oerlikons. 

127mm/38s - 5.8km to 3.5km

• Kidd:  340 damage every 3.91 seconds
• Cleveland:  440 damage ever 3.33 seconds
• North Carolina: 440 damage every 2.44 seconds
• Enterprise: 420 damage every 4.14 seconds

40mm Bofors - 3.5km to 1.5km

• Kidd: 210 damage every 1.54 seconds.
• Cleveland: 210 damage every 0.88 seconds
• North Carolina: 220 damage every 0.59 seconds
• Enterprise: 210 damage every 0.57 seconds

20mm Oerlikons - 1.5km to 0.1km

• Kidd: 110 damage every 0.73 seconds
• Cleveland: 150 damage every 0.28 seconds
• North Carolina: 140 damage every 0.32 seconds
• Enterprise: 180 damage every 0.26 seconds

There is a lot of variation here.  It means we cannot simply look at what AA mounts a given ship has, or what the DPS values are listed in port to appraise how good anti-aircraft firepower for a given ship is supposed to be.  The performance of Continuous Damage is currently flawed and this exaggerates some the disparities in performance we're seeing.  Ships reliant upon their long range AA to keep them safe aren't performing optimally right now -- German, battleships cruisers and Atlanta, I'm looking at you.  For those frustrated with the current AA mechanics -- you're right to feel that way.  Hopefully this information kindles some small bit of hope that the problems are recognized and some good changes are coming.

Provided nothing else breaks, of course.

[exray0]

Excellent info Mouse, thank you.

Doesn't really play into the "everything is fine" narrative from WG. I am also a bit skeptical that the "bug" isn't a "feature" as the initial delay in AA DPS enables WGs goal of allowing a strike to get through but making it costly in the end. Making the ramp up time slow certainly helps that. 

It also further solidifies my opinion that CV was not ready for ranked season 12 and reduces my confidence in this developer. 

[Skpstr]

Excellent post!

I was under the impression that sector reinforcement just increased DPS by a percentage, but it looks much more worthwhile now.

Fixing that bug ought to be top priority!

[SilverPhatShips]

Good info thanks mouse

[Jester_of_War]

Thank you @LittleWhiteMouse. I'm going to have to reread this a couple times to totally understand it. It's awesome that you put so much effort into helping the rest of us understand what is going on. Thanks for making the mechanics transparent. And also nudging Wargaming to make sure it's all working properly.

[Khafni]

I learn something with each of your articles. Thanks LWM!

[Umikami]

27 minutes ago, LittleWhiteMouse said:

For those frustrated with the current AA mechanics -- you're right to feel that way.

Wow, just truly excellent work; thank you for your efforts and this informative post. HUGE thumbs up Tiger!

[10T0nHammer]

Hopefully, this is allowed, but there is an interesting post on WoWS subreddit about this very topic. The Problem with Continuous AA. The quick and dirty is that the problem with AA is that it isn't effective until you reach a critical mass of damage vs. the health of the plane. I recommend the read.

[Sabot_100]

Just wondering, does the facing of the AA mount have any effect? Does an attack on the port side of a Iowa face 10 (5x2) 5" or 20? Might make a huge difference if one side of you ship has been hammered. Or is all surviving guns count?

[LittleWhiteMouse]

4 minutes ago, 10T0nHammer said:

Hopefully, this is allowed, but there is an interesting post on WoWS subreddit about this very topic. The Problem with Continuous AA. The quick and dirty is that the problem with AA is that it isn't effective until you reach a critical mass of damage vs. the health of the plane. I recommend the read.

This is the other side of the puzzle.  In theory high alpha strikes should be the missing link which smooths out the influence of RNGeebus.  The idea would be that your large caliber guns get two to four good licks in and you'd have a pretty good chance that at least one plane would be at significantly lower health by the time your medium caliber, rapid fire guns begin chewing them up during the attack run.  I've said it once and I'll say it again, you don't need to cause very many casualties to aircraft carriers to begin depleting their reserves.  For some carriers, the loss of as little as two to three planes per squadron is unsustainable.

Buffing long range guns to be able to deal those big chunks of damage will help accomplish this.  RNGeebus might still give you the middle finger on occasion, but at least the proper tools will be in place.

[LittleWhiteMouse]

4 minutes ago, Sabot_100 said:

Just wondering, does the facing of the AA mount have any effect? Does an attack on the port side of a Iowa face 10 (5x2) 5" or 20? Might make a huge difference if one side of you ship has been hammered. Or is all surviving guns count?

Facing of the AA mounts doesn't matter.

[10T0nHammer]

2 minutes ago, LittleWhiteMouse said:

uffing long range guns to be able to deal those big chunks of damage will help accomplish this.

And bring my poor Atlanta back to AA deathwall it used to be. Those 127s don't do a whole lot to deter CVs.

[ElvenRed]

Interesting... the delayed damage is a bug... when I noticed it I assumed it was made like that so the CV had some time to turn around and run in case it happened upon the AA bubble of a ship that had the same range as it's air conceal

[Kapitan_Wuff]

Very interesting, I have a much better understanding of the crap current AA mechanics.

[Edgecase]

Cool. Good to know that our initial models of how this worked were correct.

FWIW, the value displayed in port IS an accurate representation of the theoretical aura DPS if you squint really hard and remember to multiply by the listed accuracy factor. In reality, as you say, the discrete tick time on some of the larger mounts starts to make a huge difference in terms of how much real damage you can deal.

Finally, a small note on something I always find confusing: AA ticks don't seem to register their damage immediately. I think the game spawns a quasi-projectile for each tick that has to reach your plane before it actually takes the damage, and that fake (invisible) projectile actually has a rather slow velocity. This is why planes frequently take damage and get shot down even after they leave the actual AA aura range -- the invisible damage tick boogeyman was already in the air. It's also why the "Incoming AA" symbol stays on the screen long after AA has stopped shooting. While there's probably some interesting tricks you can do with the doppler effects of approaching vs. retreating against such an effect, the main consequence I've noticed is that it's really hard to tell which aura just wrecked your squadron on the way out.

[dgr_874]

“HMS Thunderer, the upcoming tier 10 premium Royal Navy battleship.“

I thought this was going to be an alternate ship in the tech tree?

 

[LittleWhiteMouse]

Just now, dgr_874 said:

I thought this was going to be an alternate ship in the tech tree?

According to some savvy code-spelunkers on Reddit, Thunderer is apparently encoded as a premium.  This may change (she's not on the live servers yet as far as I know), but she holds to the patterns seen previously, she's likely to be made available for coal, steel or free experience.

[dgr_874]

Just now, LittleWhiteMouse said:

According to some savvy code-spelunkers on Reddit, Thunderer is apparently encoded as a premium.  This may change (she's not on the live servers yet as far as I know), but she holds to the patterns seen previously, she's likely to be made available for coal, steel or free experience.

Thank you for the clarification!

[Mizzerys_Fate]

You didn't mention AFT at all.

It says, " increases efficiency of medium- and long-range AA mounts"

It ALSO says "damage per second within explosion radius of shells fired from medium- and long-range AA defenses" +15%.

.....

So what does " efficiency " actually mean?

 

[Carrier_Ikoma]

1 hour ago, LittleWhiteMouse said:

"But Mouse," you say, "your last example sounded hyperbolic.  Surely there's no way for aircraft to pass through an aura and take zero damage.  Shouldn't the AA guns open fire the moment an aircraft comes into range?"  Yes, yes they should.  They don't, but they should.

 

Despite this, cruisers with concealment close to or the same as their AA range can still damage squadrons before they can turn away/disengage - before the ship even renders.

If WG makes AA damage "instant" like that, air concealment should be nerfed a bit to allow aircraft a better chance to avoid them.

[Ironshroud]

1 hour ago, LittleWhiteMouse said:

 I mean, how am I supposed to properly evaluate the relative effectiveness of AA firepower if I don't understand the fundamentals? 

Since the change over that's what I've been wondering as well. Thanks very much for the good work on this.

[LittleWhiteMouse]

2 minutes ago, dEsTurbed1 said:

You didn't mention AFT at all.

It says, " increases efficiency of medium- and long-range AA mounts"

It ALSO says "damage per second within explosion radius of shells fired from medium- and long-range AA defenses" +15%.

.....

So what does " efficiency " actually mean?

Advanced Fire Training affects flak explosions and flak explosions only (providing a 15% increase to damage).  Flak explosions are already near instant-death for any aircraft that stumble into them and they're all too easy to avoid for expert players.  This makes Advanced Fire Training one of the least effective AA skills for its point investment currently.

[Daniel_Allan_Clark]

Fascinating.

[Mizzerys_Fate]

8 minutes ago, LittleWhiteMouse said:

Advanced Fire Training affects flak explosions and flak explosions only (providing a 15% increase to damage).  Flak explosions are already near instant-death for any aircraft that stumble into them and they're all too easy to avoid for expert players.  This makes Advanced Fire Training one of the least effective AA skills for its point investment currently.

Thank you my friend

[Helstrem]

@LittleWhiteMouse Please correct me if I am wrong, but my understanding is that an attack by fast planes can completely avoid the continuous damage from slow firing guns on both the way in and the way out because the guns don't start their cooldown to fire until an aircraft enters the range band for those guns.  Once the planes have passed through the band on the way in, doing so fast enough to avoid being shot due to the bug, the cooldown resets until a plane enters their range band again, so when that happens on the plane's way out the timer again starts and, again, the planes can get all the way through without a single pulse of damage happening.  Correct?